US: Further adverse winter weather forecast over portions of Northwest, Southwest, and West regions through at least Feb. 24 /update 1

Event

Further adverse winter weather is forecast across parts of the Northwest, Southwest, and West regions through at least Feb. 24. The adverse weather is associated with a weather system moving southward from the Pacific Northwest over California and the Great Basin Feb. 22-23. The system will bring a mix of snowfall and rainfall across the affected area over the coming days.

As of Feb. 22, the US National Weather Service (NWS) has issued winter storm warnings for parts of central and far southern California, southwestern Idaho, southern and eastern Utah, western and central Colorado, central and northeastern Arizona, and northern New Mexico. Winter storm watches have been issued for parts of far western Arizona and northeastern new Mexico. Freeze warnings have been issued for parts of central California. Winter weather advisories have been issued across much of the rest of the affected area.

The NWS's Weather Prediction Center has warned of widespread precipitation across much of the western United States through at least Feb. 24. The heaviest snow accumulations are expected over mountain ranges, with accumulations of more than 20 cm (8 inches) likely in the Wasatch and San Juan ranges and the Kaibab Plateau Feb. 22-23, with localized accumulations of more than 46 cm (18 inches) possible in these areas. Accumulations of more than 30 cm (12 inches) are likely in the southern Sierra and higher San Gabriel and San Bernadino ranges. Accumulations of more than 30 cm (8 inches) are expected in the San Juans and on the Mogollon Rim Feb. 23-24 and are also possible in the Sangre de Cristo range.

In addition to the precipitation, strong wind gusts could lead to periods of blowing and drifting snow. Sporadic power outages are likely throughout the affected area.

Transport
The winter weather will likely cause ground and air transport disruptions across much of the affected areas over the coming days. Traffic and commercial trucking delays are possible along regional highways. Difficult and dangerous driving conditions are also likely on secondary and rural roads in the affected states as maintenance crews prioritize clearing major routes. Authorities could close stretches of highways if driving conditions become too hazardous. Gusty winds may threaten to topple high-profile vehicles throughout the affected area. Flight delays and cancellations are likely due to ground stops and deicing operations at airports in the region.

Advice

Monitor local media for updated weather information. Verify road conditions before driving in areas where heavy snowfall is forecast. Allow extra time to reach destinations in these areas and carry an emergency kit and warm clothes if driving is necessary, especially on secondary or rural routes that could become impassable. If routing shipments by truck through the affected area, plan accordingly for delivery delays. Confirm flights. Charge battery-powered devices in the case of prolonged electricity outages.

Resources

US National Weather Service
US Road Conditions
Weather Prediction Center